Excavator



Filed June 22, 1937 4 Sheets-Sheet 1 Mm) r WV Mar h 1 1 39- w L.SHACKLETON M EXCAVATOR Filed June 22, 1937 4 Sheets-Sheet 2 March 14,1939. w. L. S-HACKLETON EXCAVATOR 4 Sheets-Sheet 3 Filed June 22, 1957March 14, 1939. w, L, L T N 2,150,848

EXCAVATOR Filed June 22, 1937 4 SheetsSheet 4 Patented Mar. 14, 1939UNITED STATES PATENT OFFICE EXCAVATOR Application June 22, 1937, SerialNo. 149,774 In Great Britain June 29, 1936 4 Claims.

The present invention relates to excavators of the type in whichexcavation is carried out substantially continuously as distinct fromexcavators in which the excavation is done intermit 5 tently.

One example of an excavator in which the excavation is carried outsubstantially continuously and to which the invention is particularlyapplicable is the bucket-ladder type of excavator which consists of anendless conveyor having spaced buckets, digging tools or the likemounted thereon, which are traversed over an area to be excavated andsupported on a suitable beam or jib which is pivotally connected to asuitable carriage.

According to the present invention an excavator of the continuouslyexcavating type including a supporting structure and driving gear, isprovided with an auxiliary excavating apparatus, supported by or fromsaid supporting structure and preferably driven by said driving gear,said auxiliary excavating apparatus being adapted to operate Within thefield of operation of the main excavator to effect the separate removalof part of the material within said field of operation of the mainexcavator.

The auxiliary excavating apparatus may be said to operate in advance ofthe main excavator insofar as material which would otherwise be removedby the main excavator is previously removed by the auxiliary excavatingapparatus.

The auxiliary excavating apparatus may be adjustable relatively to themain excavator in order to alter the disposition of the field ofoperation of the auxiliary excavating apparatus in the field ofoperation of the main excavator. Where however, the apparatus isrequired for use in a locality in which the material to be removed lieswithin a substantially constant region, for instance, in a strata ofsubstantially constant depth, the position of the auxiliary excavatingapparatus may be fixed, but if desired, the auxiliary excavatingapparatus may be capable of adjustment to vary the extent of its fieldof operation, for instance, by increasing the effective length of theauxiliary excavating apparatus.

The invention includes a method of mechanically excavating earth or thelike in which the earth or like is separately and simultaneously removedfrom two contiguous strata and the removal of earth from one strata,preferably the upper, at any given time, taking place further 55 intothe working face than the other.

The invention is particularly valuable for removing the overburden inclay-pits.

A suitable known type of excavator used in clay-pits is thebucket-ladder type consisting of a beam or jib which is pivotallyconnected to a 5 supporting carriage adapted to run along the edge ofthe working face'of the pit, the jib being inclined downwardly, when thecarriage runs along the upper margin of the Working face, or upwardly,when the carriage is disposed at the bottom of the pit, at a suitableangle according to the slope of the working face and the angularity ofthe jib being adjustable for instance, by suitable rope and pulleytackle operated from a derrick mounted on said carriage. The jib is 5provided with an endless belt on which spaced buckets or diggers aremounted, the lower run of the belt, when the carriage runs along theupper margin of the working face, being usually moved in the upwarddirection, and having buckets upwardly directed thereon, whereby as thebuckets move over the working face in an upward direction, and as thecarriage is traversed along the face, material is brought up to themargin of the pit. 25

Usually in clay-pits the clay strata commences some distance below thesurface of the ground and the material above the clay strata which iscalled the overburden and which is unsuitable for mixing in with theclay, must be removed,

so that the buckets of the excavator do not engage and excavate same atthe upper end of their upward movement.

The work of removing overburden in the past was usually done at leastpartially by manual digging and at considerable expense. The presentinvention enables the overburden to be removed during clay-excavation.

A suitable form of auxiliary excavating apparatus according to theinvention consists of a suitable rotary cutter or cutting apparatusadapted to revolve about an axis parallel with the direction of movementof the buckets of the main excavator and the cutting edges of which areso spaced from their axis of rotation that in their position nearest theworking surface, they project beyond the cutting surface or plane of themain excavator and preferably by a distance equal to at least one cut ofthe main excavator so that if the auxiliary excavator is located on oneside of the main excavator and the apparatus moves in one direction withthe auxiliary excavator leading, the auxiliary excavator will removesufficient material to preclude the main excavator from excavating suchmaterial on the return traverse. The auxiliary excavator may, forinstance, be arranged to'cut 2" in advance, i. e., towards the workingface, of the main excavator. When two auxiliary cutters are provided,one on each side of the jib the degree of advance of the auxiliarycutters beyond the cutting surface or plane of the main excavator. maybe less than one cut of the main excavator.

It will be appreciated that a single auxiliary excavator may be arrangedon one side of the jib. Alternatively, however, and particularly in thecase of a jib projecting upwardly from a carriage located at the bottomofthepit, two auxiliary cutters may be arranged, one on each side of thejib, for the sake of balance.

An auxiliary excavator or cutter may be con: structed as a hollow drumhaving its axis parallel to the jib of the main excavator, and supportedby the jib, the drum having openings in its surface with blades disposedon one side of such openings, whereby. material excavated by the bladespasses through the openings and into the drum. The blades and openingsmay be arranged in sets, each set extending helically along and aroundthe drum and three or more such sets of blades and. openings arepreferably provided' If desired, a number of the lower blades may beadapted for detachable connection to the drum, so as to :vary theeffective depth 'of the auxiliary excavator.

ed pulley. The lower end of the drum may be,

provided with a converging conical end which may serve as an end bearingfor the drum, and also as a discharge opening for the materialexcavated. The material excavated by the auxiliary excavator may bereturned to the bottom of the pit by a suitable chute or conveyor meanswhich may be supported partly or wholly by the jib or partly by the jiband partly by the derrick and such chute or conveyor means may beadjustable for the suitable direction of the excavated material into thepit bottom.

In a preferred arrangement, the material excavated by the auxiliaryexcavating apparatus is discharged on to a substantially horizontal orslightly downwardly inclined endless conveyor which discharges into afairly steep chute and thence to a further downwardly inclined endlessconveyor. One or both of saidendless conveyors and if desired also thechute, may be adjustable as to slope and may be pivotally supported forinstance at the upper end by the jib and may be supported at the lowerend through a suitable pulley tackle from the derrick.

An alternative form of auxiliary excavator may consist of an endlessbelt supported from the jib to run substantially parallel with the mainexcavator belt and having spaced buckets thereon. The buckets of theauxiliary excavator may, for instance be disposed opposite to those ofthe main excavator, so as to move over the face of the pit-in a downwarddirection. In this arrangement the cutting edges of the buckets of theauxiliary excavator would project in the direction of the working facebeyond the surface or plane of movement of. the cutting edges of thebuckets of the main excavator.

According to a further feature of the invention a rotary cutting device,for instance of the hollow drum type described above, may belongitudinally displaceable but angularly fixed upon a shaft extendinglengthwise of the jib, the cutter operating in advance of the mainexcavator for the removal of material at any part of the working faceprior to excavation at that part by the main excavator. This arrangementmay be employed for instance for the removal of gravel from a clay faceand may be used either with or Without an auxiliary excavator such asdescribed above for the removal of overburden.

The invention is more particularly described with reference .to theaccompanying drawings in which Figure 1 is a diagrammatic generalarrangement view of one form of construction.

Figures 2 and 3 are perspective views of the auxiliary excavator.

Figure 4 is a side elevation of the auxiliary excavator.

Figure 5 is a diagrammatic side view of 59. second, form ofconstruction, the bottom end part of the apparatus being omitted.

Figure 6 is a diagrammatic front view corresponding to Figure 5 .butwith certain of the parts in slightly different positions.

Figure '7. is a sectional view taken onthe line '!'i of Figure 6. V

Both forms of construction shown in thedrawings illustrate theapplication of the invention to excavators of the bucket ladder type inwhich spaced buckets H! are mounted on endless chains H which aresupported by a beam l2 depending from a carrier I3 running along .atrack 14. The angle of the beam l2 may be adjusted by'means of a wirerope l5 running over pulleys I6, IT at the head of a jib I8 andconnected at its end to a drum I9 driven through a suitable clutchmechanism by the prime mover of the excavator. The jib I8 is supportedby a tie-rod 2!] which is anchored toa cantilever structure 21 extendingoutwardly from the carriage, which cantilever struc-1 ture 2| alsosupports a ballast contour 22.

consists of a drum having helically arranged openings 2'! and helicallyarranged cutting blades or scoops 28 one for each opening. The materialexcavated by each blade 28 passes through the 45 At their upper ends thechains ll pass overv opening 21 and falls downwards through the drum andis discharged therefrom through the conical end 29. In the constructionillustrated there are three helical rows of openings and a bearingspindle 32 and at its lower end with a conical bearing rim 33.

The spindle 32 is journalled in a bearing 34 supported from andadjustable relatively to the beam 52 by means of a screw and nutarrangement 35 whilst at its lower end the drum is supported through theconical bearing rim 33 by conical bearing rollers 36 mounted on a plate3'! which is adjustable by means of screws and nuts relatively to'thebeam 12.

In Figures 2 and 3 the element I2a is diagrammatically shown asrepresenting a portion of extension of the beam 12.

The material excavated by the auxiliary excavator is discharged. on toan approximately horizontal conveyor 4! thence into a chute H to aninclined conveyor 42 which delivers the excavated material to the bottomof the pit as shown at 43. The auxiliary excavator is driven from apulley 45 by a wire rope 46 which engages a pulley ll at the upper endof the drum 25 (see Figures 1 and 2). The pulley ll is preferablyconically surfaced where it receives the rope to assist the tighteningof the rope on the pulley. The rope 46 includes a loop 43 in which issupported a weighted pulley 49 whereby the rope is constantly maintainedunder tension and whereby the effective length of the rope 46 isautomatically adjusted for all working positions of the beam 52 andpositions of the drum 26 relatively to the beam 52. The conveyor All isdriven from a pulley 56 through a wire rope 51 which engages a pulley 52at one end of the conveyor 46. The rope 5! includes a loop supporting aweighted pulley (not shown) as in the case of the rope 46. The conveyorG2 is driven from the shaft of the pulley 52 by means of a chain or wirerope 53.

Means not shown may be provided for adjusting the inclinations of theconveyors ii] and 42 and such means may consist of suitable wire ropeand pulley arrangements depending from the jib l8. If desired, suitablemeans may be provided for adjusting the vertical disposition of the drum2% for example the bearings 34 and 3'! may be adjustable longitudinallyof the beam 52.

It will be observed that in the condition of the excavator asillustrated in Figure 1 the buckets ii! of the main excavator areexcavating along a line 6B Whilst the auxiliary excavator is excavatingalong a line 6i parallel to the line 6i) but disposed further into theface of the pit.

Figures 5, 6 and 7 illustrate a construction in which two auxiliaryexcavators E5 and 65 are employed, one on each side of the beam [2 andin which the lowermost auxiliary excavator 56 is adjustablelongitudinally of the jib to vary the total depth of the field ofoperation of the auxiliary excavating plant. If desired, oi course, theupper auxiliary excavator 35 could be adjustable or again both of theauxiliary excavators could be adjustable.

In the construction illustrated each of the auxiliary excavators issupported from the beam l2 by means of an auxiliary frame 68, 59. Theauxiliary frame as is slidable longitudinally of the beam under theinfluence of a pair of longitudinally fixed threaded rods iii, supportedin fixed bearings H on the beam. The rods '59 pass through screwedopenings in the auxiliary frame 69 and are provided at their upper endswith bevel gears '13 which engage with co-operating bevel gears 15mounted on a shaft 75 which is rotated by a hand wheel 15.

The main conveyor for receiving the material excavated by both auxiliaryexcavators is indicated at 11.

The auxiliary excavator 55 discharges to an approximately horizontalconveyor 16 which discharges into a chute 79, the end of which isdisposed above the main conveyor H. The auxiliary excavator iii;discharges into a chute formed of two parts 3i! and 8! of which the part3! is fixed and the part til longitudinally movable with the auxiliaryexcavator 6%. The lower end of the part lies within the part 8|.

In Figure 5 the auxiliary excavator S3 is shown in a raised positionwith the chute part largely withdrawn from the part 81 whilst in Figure6 the auxiliary excavator 6'5 is in a lower position with the chute part86 largely overlapping the chute part 8|.

The chute part 8! discharges to an approximately horizontal conveyor 82which leads to a chute 83, the lower end of which is disposed above themain conveyor H. The conveyors are suitably driven by wire ropes andpulleys substantially as illustrated in Figure 1.

The auxiliary frame $9 is provided on one side with rollers 99 securedthereto and guided in a guide 94 secured to the beam l2, whilst at itsother side the guide 92 on the auxiliary frame 69 engages rollers 93mounted on the beam l2.

The driving rope 93 for the auxiliary excavator 8% passes over guiderollers 9 on its way to and from the pulley ll of the excavator drum.These guide rollers 9 are fixed to the auxiliary frame 59 and thus theirposition in relation to the pulley l! and thus the correct guidance ofthe rope 93 on to the pulley is maintained at all positions of theexcavator 66. In Figure 5 the auxiliary excavator 65 is shown in itsuppermost position and the rollers 945 and rope 93 are shown in fulllines whilst the positions of the rollers 94 and rope 93 correspondingto the lowermost position of the auxiliary excavator as shown in Figure6, are shown in dotted lines in Figure 5.

In Figure 7 the chains; of the main excavator are indicated at St and abucket of the main excavator at 95. The upper runs of the chains: arenot shown but these are guided on successive pairs of rollers 95. Thelower runs of the chains are guided between flanges 91 and 98 on themain frame.

I declare that what I claim is:

1. In an excavator of the continuously excavating type including asupporting structure, the provision of an auxiliary excavating apparatusadapted to operate within the field of operation of the main excavatorcomprising a rotatable drum supported from. said supporting structureand having openings therein, a cutting blade adjacent each openingadapted to discharge excavated material into the drum through theopening at least some of said blades being detachable and thecorrsponding openings closable and means for rotating said drum.

2. In an excavator of the bucket ladder type including a supportingstructure, the pro-vision of excavating apparatus including at least twoexcavator drtuns supported from said supporting structure, said drumshaving openings therein and being adapted to operate in contiguousfields and at least one of the drums adapted for axial adjustment toenable the drums to operate in overlapping fields whereby the combinedfield of operation of said drums can be varied in extent, a cuttingblade adjacent each opening and adapted to discharge excavated materialinto the 7 tating'said drums.

drums through the openings, and means for ro- 3. In an excavator of thebucket ladder type including a supporting structure, an auxiliaryexcavator comprising a rotatable drum supported from said supportingstructure with its axis of rotation approximately parallel to the plane,of excavation of the main excavator, said drum having openings in itscurved. Wall with a cutting blade adjacent each opening, wherebymaterial is excavated by the blades and passed into the drum throughsaid openings, said drum. having a discharge outlet at its lower end forthe discharge of excavated material from the drum.

